1. Field of the Invention
The present invention relates to an image forming apparatus and a method of controlling the image forming apparatus.
2. Description of the Related Art
Heretofore, there is known an apparatus wherein an electrostatic latent image is formed on a photosensitive drum in accordance with input image information data and developed by depositing toner on it, a developed toner image is transferred onto an intermediate transfer body, and the toner image transferred onto the intermediate transfer body is secondary-transferred onto a recording medium.
Meanwhile, Models CLC 700/800 manufactured by Canon Inc. are known as apparatus wherein images in yellow (Y), magenta (M), cyan (C) and black (Bk) are formed frame-sequentially on a sheet of recording paper without using an intermediate transfer body (i.e., without secondary transfer). In these apparatus, a full-color hard copy can be produced by superposing toner images in yellow (Y), magenta (M), cyan (C) and black (Bk) one above another. Further, in a full-color image forming apparatus such as Canon CLC 700/800, it is also possible to form a monochrome image (in black, for example) and form images on both sides of a paper sheet.
However, conventional both-side recording in such an apparatus still has a room for further improvement because the both-side recording is always performed in the same sequence or timed relation and accompanies with a problem from the standpoint of efficiency in image forming.
Further, the image forming apparatus without using an intermediate transfer body has a problem that an apparatus size is increased. If a both-side image forming function is added to that apparatus, a reversing unit for reversing a recording medium upside down would require to be added, resulting in a problem of further increasing the apparatus size.